Real World XML

XHTML Version 1.0

The standard version of XHTML, version 1.0, is just a rewrite of HTML 4.0 in XML. You can find the W3C recommendation for XHTML 1.0 at www.w3.org/TR/xhtml1. Essentially, it's just a set of DTDs that provide validity checks for documents that are supposed to mimic HTML 4.0 (actually HTML 4.01). The W3C has created several DTDs for HTML 4.0, and the XHTML DTDs are based on those, translated into straight XML. As with HTML 4.0, XHTML 1.0 has three versions, which correspond to three DTDs here:

• The strict XHTML 1.0 DTD— The strict DTD is based on straight HTML 4.0 and does not include support for elements and attributes that the W3C considers deprecated. This is the version of XHTML 1.0 that the W3C hopes people will migrate to ...